Information

Electrodes/Quivers
• Ensure your quivers are always connected to the power supply to avoid moisture pick-up.
• If you find cold electrodes in your quiver please return them to store and take new electrodes.
• Check the condition of the quiver shall be always hot, if not change the quiver. (Temp shall 70 Deg.C)
• Due to the weather the electrodes pick-up moisture and thereby giving weld defects Mainly porosity
• Be sure to return all remaining electrodes after the day work to main store.
• Storing of consumables in toolboxes which is not required for use on the same the day is totally forbidden and not allowed.
• Consumption of filler wire and electrodes should be monitored by each of the welding inspector and welding supervisor.
• During welding always keep your quiver closed for moisture control and for filler wire keep your packet closed for filler wire rust control.

Consumables mix up for Stainless steel electrodes
• The grades of SS materials are being used in the project SS 304,316L and 321(Stamping on the pipe.
• The respective Filler wire/electrodes are SS 308, 316L and 347
• Check always the grade of the material and the filler wire/electrode are matching
• In case doubts ask the inspector available with you on the site.

Earthing and grounding for welders.
• Ensure that the welder use the right earthing as per the material to be welded.
• Do not attach the earthing by welding direct to the pipe.
• Avoiding arc strike is mandatory, if happened doing PT/MT after grinding the affected area.

Seam weld orientation

• check before make any fit up that the seam weld of the pipe more than 45 degree from the bottom of the pipe specially for field run avoiding the seam to intersect with any support will be install later and avoid corrosion of pipe.
• Check the distance between to seam welds is 2 times the thickness of the thicker member at least.

Arc Strike
• Arc strike leads to localize heating and sudden cooling, leading to cracking, which is not acceptable.
• If flange raised face is damaged, the flange will leak during hydro test. The flanged need to be discarded during fabrication and replaced by new one.

Remedies:
• Shall be ground immediately
• Check by “MPI” for defect specially for cracks
• If it is too deep, refer to engineer

Porosity
• Keep a good shield against wind,
• Groove face must be kept clean from grease and liquid.
• All electrodes must be kept inside quivers
• (Quiver is connected to electricity and closes the cover),
• If you use GTAW you must use the suitable gas flow rate
(10 to 20L/min as per WPS)
• Check the Arc Length (Arc length should be within the value of used consumable diameter) and Welding Amperage.

-Handling of the spools.

Improper handling of the spools leads to spool damage (dents, distortion, paint damage …etc) so, we need to avoid such cases that waste the work time if it happened.

A: Handling of painted spools.
Precautions
1) Always use protect wraps while tying lifting belts with D-shackles
2) Use only lifting belts (no wire rope slings shall be used)
3) Place rubber packing on the tie beams where the pipe is going to be erected to avoid damage to painting, while dragging them in to the position.
4) Avoid dragging the pipes on the racks as far as possible to minimize the damage
5) Avoid hitting the pipe in the beams during erection or storing to avoid dents.
6) Place wooden planks tied to the beams while dragging the SS spools to avoid contamination of the pipes.

-Root Inspection by Welder
1) Check the root continuously and request the check by Welding Inspector to check before closing the root.
2) If any fault is noticed, please do the rectification (from inside), if accessible.
3) The availability of the lighting torch with the welders is mandatory for checking.

-Quivers
Due to the summer season we should pay more attention of the quivers.

1) Ensure your quivers are always connected to the power supply to avoid moisture pick-up.
2) If you find cold electrodes in your quiver please return them to store and take new electrodes.
3) Check the quiver is has hot electrodes and quiver is also hot, if not change the quiver.
Due to the weather the electrodes pick-up moisture and thereby giving weld defects such as porosity.

SLAG INCLUSIONS


CAUSES
• when two adjacent beads are deposited without proper over lap
• multi-pass welding with excessive undercuts in weld toe
• uneven profile of the preceding weld runs
• poor welding technique and type of flux (properties)
• access restrictions in doing a weld and cleaning the flux
• poor convex weld bead profile

PREVENTION
• clean the slag between runs by using circular wire brush (cup brush not allowed)
• use correct welding techniques to produce a smooth bead
• plan your sequence of the deposits with proper over lap
• Use the correct current and travel speed to avoid undercutting.

LACK OF FUSION

CAUSES
• narrow joint preparation
• incorrect welding parameter setting
• poor welding technique
• magnetic arc blow
• insufficient cleaning of oily or scaled surface
• LOF mainly appears in the vertical position

PREVENTION
• ensure the joint preparation is wide enough as per joint geometry
• ensure the correct welding parameters(high current, high speed, short arc length is used
• ensure the correct electrode/torch angle is used for manipulation of the arc in the joint
• Use the correct weaving limits

Seam weld orientation
• -check before make any fit up that the seam weld of the pipe at least more than 45 degree from the bottom of the pipe specially for field run avoiding the seam to intersect with any support will be install later.
• -check the distance between to seam welds is 2 times the thickness of the thicker member at least